JPS61221242A - Low heat generating rubber composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which is freed from the problem of heat generation without detriment to wear resistance, etc., by blending carbon black and an amino acid to rubber. CONSTITUTION:30-150pts.wt. carbon black and 0.1-5pts.wt., at least one or 2 or more kind of amino acid selected from cystine, lysine, arginine, hydroxylsine, glutamine and tryptophane are blended with 100pts.wt. rubber composed of natural rubber and/or a synthetic diene rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a low heat build-up rubber composition, and more particularly to a low heat build-up rubber composition that has improved heat build-up without impairing abrasion resistance.

(Prior Art) In response to social demands for resource and energy conservation, the rubber industry, particularly Tire Togane, has been actively developing fuel-efficient tires over the past few years. Low heat generation rubber compositions are essential for the development of such fuel-efficient tires.For example, especially for passenger car tires,
JP-A-57-51508, JP-A-57-5520
4. As described in Japanese Patent Application Laid-Open No. 58-86705, there is a method of using styrene-butadiene rubber (SBR) in which the groups containing bonded styrene and vinyl bonds are controlled, but these methods do not apply to SBR. It could not be applied at all to natural rubber, which is widely used in tires for heavy vehicles, especially natural rubber.

On the other hand, Japanese Patent Publication No. 50-88181, British Patent $E1
185896E, U.S. Pat. No. 2,815,856, U.S. Pat. No. 2,815,856, etc., it is described that the heat generation properties of rubber compositions are improved by adding nitrosoquinolines, nitrosoanilines, etc. . However, although such nitroso compounds do improve heat generation properties, they have the disadvantage that, especially when applied to polyisoprene rubber, they have a large decomposition effect on the polymer, significantly reducing the abrasion resistance of the rubber composition. It had

(Problems to be Solved by the Invention) The present invention cannot be applied to natural rubber as described above, or when applied to polyisoprene rubber, the disintegration effect is large or the rubber composition has a high resistance. An attempt is made to solve the problem of significantly lowering abrasion properties and provide a low heat build-up rubber composition that does not have such drawbacks.

(Means for Solving the Problems) The present inventors have conducted extensive studies with the aim of improving the above-mentioned drawbacks, and have found that when amino acids are used in combination with carbon black, they do not quickly decompose and do not generate heat. The present invention was developed by confirming that the present invention can improve the following. That is, the structure of the present invention is made by blending 30 to 150 parts by weight of carbon black and 0.1 to 5 fl parts of amino acids with 100 parts by weight of rubber made of natural rubber and/or diene-based synthetic rubber. It is a low heat generation rubber composition.

Rubbers used in the present invention include natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber, polybutadiene rubber, butyl rubber, and these rubbers can be used alone or in combination of two or more.

Amino acids used in the present invention include cystine, lysine, arginine, oxylysine, glutamine, aspartic acid, glutamic acid, serine, glycine, threonine,
These amino acids include alanine, tyrosine, tryptophan, valine, a-isine, isoleucine, histidine, α-phenylalanine, proline, methionine, etc., and preferably cystine, lysine, arginine, oxylysine, glutamine, tryptophan, etc. /@ or more can be used together. Further, the blending amount of the amino acid is 0.1 to 5 parts by weight per 100 parts by weight of rubber. If the amount is less than 0.1 parts by weight, there will be little effect on improving the heat generation of the rubber composition, and if it exceeds 5 parts by weight, not only will there be no effect in increasing the amount, but the mechanical properties of the rubber composition will deteriorate.

In the present invention, the blending amount of carbon black is 30 to
If the amount is less than 30 parts by weight, the reinforcing properties of the rubber composition will be poor, and if it exceeds 150 parts by weight, not only the heat generation properties will be significantly deteriorated, but also the physical properties such as abrasion resistance will be significantly deteriorated.

In the present invention, in addition to the above-mentioned carbon black and amino acids, compounding agents commonly used in the rubber industry, such as softeners, anti-aging agents, vulcanization accelerators, vulcanization accelerators, and vulcanizing agents, are used as necessary. can be appropriately blended.

(Examples) Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples.

Examples 1 to 8, Comparative Example 1-8 Various rubber compositions with the formulation shown in the first barley were kneaded using a Banbury mixer and evaluated for impact resilience, sol molecular weight, and abrasion resistance. did. IEI results
Shown in the table. For comparison, Comparative Example 1 is a case in which no amino acid is blended, Comparative Example 2 is a case in which 5-nitrone-8-human-mixiquino I) 7 is blended, and Comparative Example 8 is a case in which N-
The case where phenyl-p-nitrosoaniline was blended was similarly evaluated.

The evaluation method is as follows.

Repulsion elasticity: Measured according to JISK6301.

Sol molecular weight: After 48 hours of immersing the unvulcanized rubber composition in tetrahydrofuran, the remaining liquid after removing the carbon gel was stained with Toyo Soda Membrane Hlgh 5peed Liquid Chromat.
The molecular weight of the sol fraction was measured using ographHLO-3021.

Abrasion resistance: The various rubber compositions shown in Table 1 were used in the tread of a radial tire for trucks and buses with a tire size of 1000R20, and after running 50,000 kll, the shallow grooves were measured and the mileage per cod was calculated. It was calculated and expressed as an index with Comparative Example 1 set as 100.

The larger the value, the better.

As is clear from Table 1, the nitrone compound shown in the comparative example has an excellent resilience improvement effect, but the polymer has a large decomposition effect, resulting in a decrease in wear resistance, whereas the amino compound has an excellent effect on improving resilience. The rubber composition according to the present invention, which is blended with , has a slightly inferior resilience improvement effect compared to the nitroso compound, but it has a #1 polymer dissolution rate, and
It is possible to satisfy both properties of heat generation and wear resistance at the same time.

Examples 9 to 12, Comparative Examples 4 to 5 Rubber compositions prepared with the formulations shown in Table 2 were evaluated for impact resilience and abrasion resistance in the same manner as in Example 1. The results are shown in Table 2.

*From Table 2, it can be seen that the rubber composition of the present invention is capable of achieving both heat generation properties and abrasion resistance.

Table 2 Index display (effects of the invention) with the present comparative example number set as 100 As is clear from the above examples and comparative examples, the present invention applies The present invention provides a rubber composition containing carbon black and an amino acid, which generates low heat generation without increasing the quick decomposition effect or significantly reducing the abrasion resistance of the rubber composition as in the past. You can realize your sexuality.

Claims (1)

[Claims] 1. 100 parts by weight of rubber made of natural rubber and/or diene-based synthetic rubber is blended with 30 to 150 parts by weight of carbon black and 0.1 to 5 parts by weight of amino acids. Low heat generation rubber composition. 2. Amino acids are cystine, lysine, arginine, oxylysine, glutamine, aspartic acid, glutamic acid,
serine, glycine, threonine, alanine, tyrosine,
The rubber composition according to claim 1, wherein the rubber composition is tryptophan, valine, leucine, isoleucine, histidine, α-phenylalanine, proline, or methionine. 3. The rubber composition according to claim 1, wherein the amino acid is cystine, lysine, arginine, oxylysine, glutamine or tryptophan.